I changed antihistamines from Clarinex (Claritin-type drug) to hydroxyzine generic (also supplied as brand names Atarax or Vistaril in the USA). I made this change when I became aware that IC patients routinely use this as a treatment option.

I take 25 mg at night (about 25% of the normal adult dose, cos' I'm a conservative guy). The first few nights I slept like a log and had to take a few naps the next day too, but this wore off and now I am no longer sleepy in the daytime. After a few days I noticed I was reacting less to food, and yesterday I pulled out all the stops, eating cheese, dried pineapple, bananas (gasp!), mango and more (all no-nos for me). I thought to myself: "Let's see. I should wake up in the wee hours in awful stomach and bowel pain."

Imagine my delight when I woke not at 2am/3am but at 6.30am (normal for me) with no pain anywhere! This is after suffering such pains for over a decade, and even having several gastroscopies, gallium scans and barium enemas to find the cause (unsuccessfully)!

WOW!

On the downside I notice a slight tightness or occasional mild sting around my prostate/bladder area, possibly due to the well-known antihistamine anticholinergic (antimuscarinic) effect. I should offset this with something like an alpha-blocker perhaps.